Development tooling and repository files #214

Development tooling and repository files to update (global audit after the releases, bridges-audit.md #154 to #166 and #169, process-bundle-audit.md #115):

• Add a .gitattributes to exclude the development files from the Composer archive, remove the unused package.json #154 CONTRIBUTING.md, "Deprecations notices": @trigger_error(..., E_USER_DEPRECATED) instead of trigger_deprecation(), wrong versions, SYMFONY_DEPRECATIONS_HELPER=0 while the tests use failOnDeprecation.
• #154 - Add a .gitattributes to exclude the development files from the Composer archive, remove the unused package.json #155 The .docker image has neither pcov nor Xdebug: the coverage, and the tests reported as risky by the CI, cannot be checked locally. Install pcov (built from its tarball, PECL downloads are unreliable).
• #156 - Trigger a deprecation at runtime in LogRecord::contextIsEmpty() with trigger_deprecation() #157 (bridges) KernelTest::testTasksAreResolvedByCode is skipped with process-bundle < 5.4, dead code since ^5.4 is required.
• CI: test the lowest dependencies #158 PHP-CS-Fixer: @PHPUnit7x5Migration:risky → @PHPUnit10x0Migration:risky (PHPUnit 11.5 at least); @DoctrineAnnotation is useless (no annotation).
• Full control over the launch form fields (type, options, constraints) through ui options #160 (ui) Makefile: the twig-cs-fixer target is described as "Run Rector".
• #160 - Full control over the launch form fields (type, options, constraints, default) through the new form UI option #161 Makefile: no .PHONY; fake src/vendor target (composer install run every time): vendor target depending on composer.json; bash runs exec on a container supposed to be started.
• Add a process configuration example to the bug report template #162 .gitignore: Flex blocks without recipe, GEMINI.md, webpack-encore, vendor-sf3/4/5 (process-bundle, with the Blackfire .env.dist, Users: API token replaced by a simple GET request (no CSRF token) #115).
• #162 - Add a process configuration example to the bug report template #163 Issue and pull request templates: "Cookbooks" checkbox missing in the bridges (they all have docs/cookbooks/), no contact_links (security policy, documentation).
• Use the PHP 8.3 to 8.5 functions through the Symfony polyfills, and configure Rector accordingly #164 README: badges (CI, Packagist, license); Installation section missing in the bridges; the rest and soap links point to the French Wikipedia.
• #164 - Use the PHP 8.3 to 8.5 functions through the Symfony polyfills, and configure Rector accordingly #165 LICENSE: heterogeneous copyright, while the PHP headers all say "Clever-Age".
• Doctrine ORM 2: readonly entity properties fail with the legacy proxies #166 composer.json: no support; allow-plugins: symfony/runtime while symfony/runtime is not required.
• Security configuration overrides the application main firewall, and cannot be disabled #169 dependabot.yml: 4-space indentation without final line break (2 spaces in process-bundle).